Inductive converters such as the buck converter, the boost converter, the buck-boost converter, the Cuk converter, and the single-ended primary-inductor converter (SEPIC), may offer numerous advantages. However, care should be taken to protect the inductor(s) by keeping the inductor currents within predefined limits. In particular, if inductor currents pass the point where the inductor cores reach magnetic saturation, the inductors' impedance drops almost all the way to the (small) resistance value of the wiring. The inductor current accordingly exhibits a sharp increase beyond this point, typically causing an excessive amount of heat energy to be dissipated in the inductor, leading to a rapid electrical component failure.
It is relatively straightforward to design the inductive converter circuitry when the input voltage is expected to be relatively well controlled. However, where the input voltage is expected to vary over a wide range (e.g., 2 to 40 volts), it becomes significantly more challenging to achieve a consistently high conversion efficiency while providing adequate protection to the inductors. Typically, a significant number of additional components are required, with corresponding areal and commensurate power requirements.